title: A novel peptidoglycan-associated lipoprotein (PAL) found in the outer membrane of Proteus mirabilis and other Gram-negative bacteria.
abstract: A novel peptidoglycan-associated lipoprotein (PAL) was found in the cell envelope of Proteus mirabilis. This protein showed the following properties: (1) The apparent molecular weight in sodium dodecyl sulfate (SDS) polyacrylamide gel was 18,000. (2) The protein was present in the cell envelope in a form very closely, but not covalently, associated with the peptidoglycan layer. (3) The protein was recovered predominantly from the outer membrane fraction after separation of the cell envelopes. (4) [1-14C]Palmitic acid and [2-3H]glycerol were incorporated into the protein. (5) The protein contained covalently linked fatty acids (about 3 mol of fatty acid per mol of protein). (6) An unidentified compound was present in the hydrolysate of the protein. These properties, except for molecular weight and non-covalent association with the peptidoglycan, showed resemblance to those of Braun's lipoprotein. However the protein was distinct from Braun's lipoprotein in regard to amino acid composition. A similar peptidoglycan-associated lipoprotein (PAL) was present widely in the cell envelopes of various Gram-negative bacteria. P. mirabilis contains about twelve times as much PAL as Escherichia coli. Antiserum against PAL of P. mirabilis was cross-reactive against PAL of E. coli, but not against Braun's lipoprotein of E. coli.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D001425:Bacterial Outer Membrane Proteins; D002462:Cell Membrane / Q000032:analysis; D004755:Enterobacteriaceae / Q000032:analysis; D029968:Escherichia coli Proteins; D005227:Fatty Acids / Q000032:analysis; D005779:Immunodiffusion; D008074:Lipoproteins / Q000302:isolation & purification* / Q000378:metabolism; D008970:Molecular Weight; D010457:Peptidoglycan / Q000302:isolation & purification* / Q000378:metabolism; D011509:Proteoglycans; D011513:Proteus mirabilis / Q000032:analysis*; D011549:Pseudomonas / Q000032:analysis
chemical_list: D000596:Amino Acids; D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; C031163:ExcC protein, E coli; D005227:Fatty Acids; D008074:Lipoproteins; D010457:Peptidoglycan; D011509:Proteoglycans; C069988:PplA protein, Legionella pneumophila